Handling datetimes when binding

Signed-off-by: Adam Kalnas <a.kalnas@modcloth.com>
Handling nulls when binding in prepared statements

Was previously serializing them as the string '<nil>'.
Signed-off-by: Adam Kalnas <a.kalnas@modcloth.com>
Merge pull request #3 from modcloth/handle-datetimes-and-null-in-prepared-statements

Handle datetimes and null in prepared statements